Pro Modified

Pro Modified, also known as Pro Mod, is a class or division in the sport of drag racing which began in the IHRA sanctioning body.

Overview

This division has specific rules about engines, components, bodies, etc. Pro Modifieds can either be raced on 1/4 mile or 1/8 mile tracks. Usually, the IHRA races Pro Mod cars on the 1/4 mile, resulting in low-to-mid 6 second passes, while the ADRL (American Drag Racing League) races strictly on 1/8 mile track setups, allowing for high 3 second-to low 4 second passes. Pro Modified has only been around for about 15 years, whereas other classes are much older. Despite Pro Modified cars being slower than the Top Fuel or Funny Car classes , it has become one of the most popular divisions of the sport. The Pro Modified division was a spin-off of the IHRA's Top Sportsman division but with fewer limitations, allowing for significantly higher performance. The American Drag Racing League's top three classes (Pro Extreme, Pro Nitrous, and Extreme 10.5) are comprised of all Pro Modified vehicles, making the ADRL one of the fastest growing and most popular drag racing organizations. Due to the near-limitless engine/drivetrain combinations and incredibly lenient rule system used by most Pro Modified racing organizations, competing teams in this series of drag racing have virtually every freedom to make their car as fast and competitive as it can possibly be.

Engines

The rules of engine performance in Pro Modified are simple and straight forward: the engine can either have up to 527 cubic inches and be supercharged and methanol fueled, or it can have a larger 820 cubic inch engine that utilizes nitrous oxide and gasoline. For the first time, turbocharged engines were permitted for the 2008 IHRA season. These engines put out an extremely large amount of horsepower, some at approximately 2500 H.P. The engines propel the cars down the track at speeds of over 200 mph. There are weight limits, according to the type of engine used, 2375 lb. for nitrous powered cars, and 2700 lb. for supercharged (or blown) cars. Most supercharged engines are based on Chrysler's 426 Hemi engine. The exhaust system is similar to that of a Funny Car. Simple short header pipes bolted onto the engine block heads extend down from the motor and curve upward just before reaching the ground. The exhaust pipes are visible just behind the front wheels of the vehicle. Most of the time, each exhaust port on the heads has its own individual pipe, but occasionally the four pipes on each side of the engine block converge into one single header collector on each side of the motor, resulting in two exhaust pipes instead of eight.

Bodies

The body of a Pro Modified car is somewhat similar to a Pro Stock race car, yet also radically different at the same time. Whereas Pro Stock cars retain street identification, Pro Modified cars' bodies are just that: modified . Pro Mod race cars have either a forward-facing (with the opening in front) hood scoop for nitrous injected cars, or the hood may be cut to allow a supercharger to be fitted through onto a blown motor. Also, a Pro Modified car is usually fitted with a long, flat wing extending from the base of the rear windshield and past where the lip of the trunk lid would be on a normal car. This wing aids in downforce and stability, and helps keep the car on the ground. Many body styles are represented in the Pro Mod class. Everything from a Plymouth Superbird to a Volkswagen Beetle has been seen at the dragstrip in Pro Mod fitting. Some of the more common body styles include the Chevrolet Corvette and Camaro, the Ford Mustang, and Studebaker vehicles. Small pick-up trucks, like the Chevrolet S-10 also make for popular Pro Mod vehicle choices.The material with which the body of a Pro Modified race car is constructed out of is a fiberglass material, similar to the material used in the bodies of most race cars.The IHRA banned any body style of a current legal Pro Stock car from being used in Pro Modified in 2008.

Transmissions

A Pro Modified car may have anywhere from a 3-speed transmission (more commonly used on 1/8 mile tracks) to a 5-speed transmission (used mostly on 1/4 mile tracks). An automatic transmission or a manual transmission may be used with any combination of rear-end gears.

See also

*Top Fuel
*Funny Car
*Pro Stock
*IHRA
*Scotty Cannon